Outliner: Avoid rebuilding tree on selection/active changes

We can avoid the rather expensive outliner tree rebuilds and only redraw
if nothing but the selection or active item changes. This should give a
bit of speedup for heavy scenes.

For this to work I had to correct a few notifiers, some were only
sending selection/active change notifiers that actually did things like
adding objects. I also added a more precise notifier type for when the
active collection changes. At the notifier subtype/action level we're
not even close to running out of bits, so this should be fine.
Also had to correct a wrong notifier check (was using `&` rather than
`==`).

1 files changed, 14 insertions, 4 deletions

diff --git a/source/blender/editors/space_outliner/space_outliner.c b/source/blender/editors/space_outliner/space_outliner.c
index b14afed81dd..6854367d975 100644
--- a/source/blender/editors/space_outliner/space_outliner.c
+++ b/source/blender/editors/space_outliner/space_outliner.c
@@ -114,6 +114,8 @@ static void outliner_main_region_listener(wmWindow *UNUSED(win),
       switch (wmn->data) {
         case ND_OB_ACTIVE:
         case ND_OB_SELECT:
+          ED_region_tag_redraw_no_rebuild(region);
+          break;
         case ND_OB_VISIBLE:
         case ND_OB_RENDER:
         case ND_MODE:
@@ -121,15 +123,23 @@ static void outliner_main_region_listener(wmWindow *UNUSED(win),
         case ND_FRAME:
         case ND_RENDER_OPTIONS:
         case ND_SEQUENCER:
-        case ND_LAYER:
         case ND_LAYER_CONTENT:
         case ND_WORLD:
         case ND_SCENEBROWSE:
           ED_region_tag_redraw(region);
           break;
+        case ND_LAYER:
+          /* Avoid rebuild if only the active collection changes */
+          if ((wmn->subtype == NS_LAYER_COLLECTION) && (wmn->action == NA_ACTIVATED)) {
+            ED_region_tag_redraw_no_rebuild(region);
+            break;
+          }
+
+          ED_region_tag_redraw(region);
+          break;
       }
-      if (wmn->action & NA_EDITED) {
-        ED_region_tag_redraw(region);
+      if (wmn->action == NA_EDITED) {
+        ED_region_tag_redraw_no_rebuild(region);
       }
       break;
     case NC_OBJECT:
@@ -181,7 +191,7 @@ static void outliner_main_region_listener(wmWindow *UNUSED(win),
     case NC_MATERIAL:
       switch (wmn->data) {
         case ND_SHADING_LINKS:
-          ED_region_tag_redraw(region);
+          ED_region_tag_redraw_no_rebuild(region);
           break;
       }
       break;